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Linear System Analyzer

Analyze time and frequency responses of linear time-invariant (LTI) systems

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描述

TheLinear System Analyzerapp lets you analyze time and frequency responses of LTI systems. Using this app, you can:

  • View and compare the response plots of SISO and MIMO systems, or of several linear models at the same time.

  • Generate time response plots such as step, impulse, and time response to arbitrary inputs.

  • Generate frequency response plots such as Bode, Nyquist, Nichols, singular-value, and pole-zero plots.

  • Inspect key response characteristics, such as rise time, maximum overshoot, and stability margins.

Available Plots

Linear System Analyzercan generate the following response plots:

  • Step response

  • Impulse response

  • Simulated time response to specified input signal

  • Simulated time response from specified initial conditions (state-space models only)

  • Bode diagram (magnitude and phase, or magnitude alone)

  • Nyquist plot

  • Nichols plot

  • Singular value plot

  • Pole/zero map and I/O pole/zero map

Linear System Analyzer app

Open the Linear System Analyzer App

  • MATLAB®Toolstrip: On theAppstab, underControl System Design and Analysis, click the app icon.

  • MATLAB command prompt: EnterlinearSystemAnalyzer.

Examples

Programmatic Use

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linearSystemAnalyzeropens theLinear System Analyzerapp with no LTI systems to analyze. To specify a system to analyze, selectFile>Import.

linearSystemAnalyzer(sys1,sys2,...,sysn)opensLinear System Analyzerand displays the step response of one or moredynamic system models,sys1,sys2, ...,sysn. Such models include:

  • Numeric LTI models such astf,zpk, orssmodels.

  • Identified models such asidtf,idss, oridproc(requires System Identification Toolbox™ software).

  • Generalized LTI models such asgenssorussmodels. For generalized LTI models without uncertainty,Linear System Analyzerplots the response of the nominal value of the model. For generalized models with uncertainty, the app plots the responses of 20 random samples of the uncertain system. (Uncertain models require Robust Control Toolbox™ software.)

linearSystemAnalyzer(sys1,LineSpec1,sys2,LineSpec2...,sysn,LineSpecn)specifies the line style, marker, and color of each response plot. Specify plot styles using one, two, or three characters. For example, the following code uses red asterisks for the response ofsys1, and a magenta dotted line for the response ofsys2.

linearSystemAnalyzer(sys1,的r - *,sys2,'m--');

For more information about configuring this argument, see theLineSpecinput argument of theplotfunction.

linearSystemAnalyzer(plottype,___)opensLinear System Analyzerand displays the response types specified byplottype. You can use this syntax with any of the previous input argument combinations. Theplottypeargument can be any one of the following:

  • “步骤”— Step response.

  • 'impulse'— Impulse response.

  • 'lsim'— Linear simulation plot. When you use this plot type, the Linear Simulation Tool dialog box prompts you to specify an input signal for the simulation.

  • 'initial'— Initial condition plot (state-space models only). You can use theextras参数指定初始状态。如果you do not, the Linear Simulation Tool dialog box opens and prompts you to specify an initial state for the simulation.

  • 'bode'— Bode diagram.

  • 'bodemag'— Bode magnitude diagram.

  • 'nyquist'— Nyquist plot.

  • 'nichols'— Nichols plot.

  • 'sigma'— Singular value plot. (Seesigma).

  • 'pzmap'— Pole/zero map.

  • 'iopzmap'— Pole/zero map of each input/output pair of the LTI system.

To openLinear System Analyzerwith multiple response plots, use a cell array of up to six of these plot types for theplottypeinput argument. For example, the following command opens the app with a step response plot and a Nyquist plot for the systemsys.

linearSystemAnalyzer({“步骤”;'nyquist'},sys)

linearSystemAnalyzer(plottype,sys1,sys2,...,sysn,extras)specifies additional input arguments specific to the type of response plot.extrascan be one or more of the input arguments available for the function corresponding to the plot type except theplotoptionsanddataoptionsarguments. For example, supposeplottypeis“步骤”. Then,extrasenables you to use the additional arguments that you could use with thestepcommand, such as the desired final time,Tfinal. Thus, the following command opens the app with a step response plot ofsys, with a final time ofTfinal.

linearSystemAnalyzer(“步骤”,sys,Tfinal)

Ifplottypeis'initial', you can useextrasto supply the initial conditionsx0, and other arguments such asTfinal. For example:

linearSystemAnalyzer('initial',sys,x0,Tfinal)

To determine appropriate arguments forextras, see the reference pages of the functions corresponding to each plot type, such asstep,bode, orinitial.

h = linearSystemAnalyzer(___)returns a handle to theLinear System Analyzerfigure. You can use this syntax with any of the previous combinations of input arguments. Use the handle to modify previously openedLinear System Analyzerinstances, as described in the next two syntaxes.

linearSystemAnalyzer('clear',h)clears the plots and data from theLinear System Analyzercorresponding to handleh. To clear multiple app instances at once, sethto a vector of handles.

linearSystemAnalyzer('current',sys1,sys2,...,sysn,h)adds the responses of the systemssys1,sys2, ...,sysnto theLinear System Analyzercorresponding to handleh. To update multiple app instances at once, sethto a vector of handles. If the new systems have different I/O dimensions from the currently displayed systems, the app clears the existing responses and displays only the new ones.

Version History

Introduced in R2015a

See Also

Apps

Functions